When designing control systems, there are times when it is not cost effective to use a Programmable Logic Controller [PLC] with high physical input/output [I/O] and special extension modules for analog sensing. Such is the case with low profit margin, low cost, low production commercial applications.
Certain prior systems could be expanded to provide a plurality of channels to a PLC. However, such systems required a numerical input in addition to the channel input.
The present system provides a low cost way to expand a single high speed input of a low cost, low physical I/O PLC into multiple 0-10 vdc high resolution analog/low speed digital sensing points. The system utilizes no additional inputs or outputs for synchronization or read/write operations—just a single wire connection will expand one high speed PLC input to a plurality (e.g., 8, 16, etc.) of analog/digital channels, freeing up the remaining PLC inputs for other uses.